A neonate has a single wide pulse pressure, a pansystolic murmur along the left sternal border, and mild cyanosis. Chest X-ray shows cardiomegaly with increased pulmonary vascular markings. Echocardiography demonstrates a single large arterial trunk overriding a large subarterial ventricular septal defect, with the origin of both coronary arteries from this trunk. Which genetic association should be specifically looked for?

• A Trisomy 21
• B Turner syndrome (45,X)
• C 22q11.2 microdeletion (DiGeorge syndrome) ✓
• D Holt-Oram syndrome (TBX5 mutation)

Explanation

Persistent truncus arteriosus results from failure of septation of the truncus arteriosus by neural crest derived tissue, and about one third of patients have 22q11.2 deletion with thymic aplasia, hypocalcaemia, and T cell deficiency. Trisomy 21 classically associates with atrioventricular septal defect, Turner syndrome with coarctation, and Holt-Oram with secundum atrial septal defect, so these associations kill the other options.

Reference: Nelson Textbook of Pediatrics, 21st ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.